Is a king and an emperor the same thing?

Answer 1

Not really, Emperors are more focused on building an empire and that title is the name for a leader of a country focused on conquest while kings may or may not invade other regions they aren't know for it.

Answer 2

No. A dictator controls a country (usually aggressively through fear) and control all aspects of society and most also try to control what people do in their spare time, what religion they have, what jobs they have and even the way they think and feel about the government.

Emperors are similar to dictators in that they control through force and do not allow any criticism of the government. However, the word emperor is usually used when describing an empire or federation/confederation/dominion involving multiple countries or multiple ethnic groups. A lof of people nowadays who call themselves emperor are actually dictators but the title emperor sounds more important. Emperors are commonly known for massacres and for warfare and have a reputation of abuse and unnecessary killing or torture of their people.

In terms of human rights, dictators can choose to take them away if they want but emperors make the people they control 'subjects' - subjects are people who have far fewer human rights and reduced freedom.